Prosthetic aortic heart valves

ABSTRACT

A prosthetic aortic valve includes an annular, annulus inflow portion that is designed to reside in or near the patient&#39;s native aortic valve annulus, and an annular, aortic outflow portion that is designed to reside in the patient&#39;s aorta downstream from at least a portion of the valsalva sinus. The annulus inflow portion and the aortic outflow portion are connected to one another by a plurality of connecting struts that are confined to regions near the commissures of the patient&#39;s native aortic valve. The connecting struts are designed to bulge out into the valsalva sinus to help anchor the prosthetic valve in place. The valve is circumferentially collapsible to a relatively small diameter for less-invasive delivery into the patient. The valve circumferentially expands to a larger operational diameter when deployed at the implant site.

The present application is a continuation of U.S. patent applicationSer. No. 15/206,427, which is a continuation of U.S. patent applicationSer. No. 14/261,628, filed on Apr. 25, 2014, now U.S. Pat. No.9,421,097, which is a continuation of U.S. patent application Ser. No.12/733,344, filed on Feb. 24, 2010, now U.S. Pat. No. 8,728,154, whichapplication is a national phase entry under 35 U.S.C. § 371 ofInternational Application No. PCT/US08/09950 filed Aug. 21, 2008, whichclaims priority from U.S. Provisional Patent Application No. 60/966,113,filed Aug. 24, 2007, the disclosures of all of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

PCT patent application No. PCT/US08/07015, filed Jun. 4, 2008, showsprosthetic heart valves that are annularly collapsible for delivery intoa patient, and then re-expandable at the implant site in the patient.(The above document will be referred to hereinafter as theabove-mentioned reference, and it is hereby incorporated by referenceherein in its entirety.) The prosthetic heart valves shown and describedin the above-mentioned reference typically include an annular supportingstructure or stent frame (e.g., of a highly elastic metal such asnitinol). This stent frame or stent typically includes an annulus inflowportion and an aortic outflow portion that is generally coaxial with theannulus inflow portion and spaced downstream (in terms of blood flowthrough the implanted valve) from the annulus inflow portion. Theannulus inflow and aortic outflow portions are preferably connected toone another substantially solely by connecting struts that extendbetween the annulus inflow and aortic outflow portions adjacent to thecommissure regions (also known as commissure posts having commissuretips) of the valve. By confining these connecting struts between theannulus inflow and aortic outflow portions to close proximity to thecommissure tip regions, the circumferential space between annularlyadjacent commissure tips is left relatively open, which (in the case ofaortic valve use) helps the prosthesis avoid occluding the ostia of thecoronary arteries.

Valves of this general type are intended for delivery into a patient atan implant site to which the surgeon may not have direct open access,e.g., for suturing the implanted valve in place. Good self-anchoring ofthe valve at the implant site is therefore important, and there may beself-anchoring improvements that can be made relative to embodimentsthat are shown in the above-mentioned reference.

SUMMARY OF THE INVENTION

A prosthetic aortic valve in accordance with the invention typicallyincludes an annular stent frame and a plurality of valve leafletssupported by a portion of the stent. The stent typically includes anannulus inflow portion configured for disposition adjacent a patient'snative aortic valve annulus. The leaflets are typically supported by theannulus inflow portion. The stent typically further includes an aorticoutflow portion configured for disposition in the patient's native aortadownstream from at least a portion of the patient's native valsalvasinus (also sometimes called the sinus of valsalva). The stent typicallystill further includes a plurality of connecting struts that constitutesubstantially the sole connection between the annulus inflow portion andthe aortic outflow portion. The annulus inflow portion typically definesa plurality of commissure tips that are spaced from one another in theannular direction around the annulus inflow portion. The commissure tipsare the features of the annulus inflow portion that are closest to theaortic outflow portion. Each of the above-mentioned connecting struts isconnected to the annulus inflow portion only at points that are fartherfrom the aortic outflow portion than the commissure tips. In addition,each of the connecting struts is adjacent to an associated one of thecommissure tips, and at least one of the struts is positioned fordisposition adjacent each side of each of the patient's native aorticvalve commissure tips. Each of the connecting struts is constructed tobulge radially outwardly like (and into) the valsalva sinus when thevalve is in use in a patient.

Further features of the invention, its nature and various advantages,will be more apparent from the accompanying drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified perspective or isometric view of an illustrativeembodiment of some components of a prosthetic heart valve in accordancewith the invention, in a first possible operating condition of thosecomponents.

FIG. 2 is a simplified perspective or isometric view of a structure likethat shown in FIG. 1, in another possible operating condition of thatstructure.

FIG. 3 is a simplified cross-sectional view of a patient's nativetissue, with some components of an implanted valve of this inventionvisible in that native tissue structure.

FIG. 4 is a view similar to FIG. 2 for another illustrative embodimentin accordance with the invention.

FIG. 5 is a view similar to FIG. 2 for yet another illustrativeembodiment in accordance with the invention.

FIG. 6 is a view similar to FIG. 2 for still another illustrativeembodiment in accordance with the invention.

FIG. 7a is a view similar to part of FIG. 2 for yet another illustrativeembodiment in accordance with the invention. FIG. 7a shows the leafletsof the valve open but greatly simplified. FIG. 7a also shows otherpossible components added.

FIG. 7b is a view similar to FIG. 7a for another illustrative embodimentin accordance with the invention.

FIG. 8 is a view similar to FIG. 2 for still another illustrativeembodiment in accordance with the invention.

FIG. 9 shows a portion of the FIG. 8 embodiment in another operatingcondition of the apparatus.

FIG. 10 is a simplified elevational view of a portion of yet anotherillustrative embodiment in accordance with the invention. FIG. 10 showsthe depicted component after it has been cut along an axis that isvertical in FIG. 10 and then laid out flat in the plane in which FIG. 10is drawn.

FIG. 11 is an enlargement of a representative portion of what is shownin FIG. 10.

FIG. 12 shows the FIG. 11 structure in another operating condition.

FIG. 13 is a view similar to FIG. 10 for another illustrative embodimentin accordance with the invention.

FIG. 14 is a simplified view looking down on the inflow portion of anillustrative embodiment of a prosthetic heart valve in accordance withthe invention.

FIG. 15 is a simplified view looking down on the inflow portion ofanother illustrative embodiment of a prosthetic heart valve inaccordance with the invention.

FIG. 16 is a view similar to FIG. 13 for another illustrative embodimentin accordance with the invention.

DETAILED DESCRIPTION

Many of the principles employed in the prosthetic valves that are shownand described in the above-mentioned reference can be employed in valvesin accordance with this invention. Accordingly, the descriptions of somefeatures herein can be somewhat abbreviated because more completeinformation is already available from the above-mentioned reference. Tofacilitate comparison, the reference numbers that are used herein forcomponents that are at least generally similar to components in theabove-mentioned reference are often (although perhaps not always)related by integer multiples of 1000 to the reference numbers used forthose generally similar components in the above-mentioned reference.Thus, for example, component 5010 herein is generally similar to any ofcomponents 10, 1010, 2010, 3010, 4010, 5010, etc., in theabove-mentioned reference.

FIG. 1 shows some components of an illustrative prosthetic heart valvein accordance with the invention in an annularly or circumferentiallycollapsed condition for delivery into a patient via relativelysmall-diameter delivery apparatus. (FIG. 1 has been simplified asexplained in more detail in the next paragraph.) Such small-diameterdelivery can be used to avoid full open-chest/open-heart surgery. FIG. 2shows a valve generally like the valve shown in FIG. 1 (although withsome differences from what is shown in FIG. 1) after annular orcircumferential re-expansion (e.g., via the use of highly-elastic,self-expansion). FIG. 2 thus shows a valve in its deployed condition(i.e., the condition it has when implanted in a patient).

All of the many embodiments shown and described in this specificationare annularly or circumferentially collapsible to a delivery conditionlike that generally illustrated by FIG. 1, and then annularly orcircumferentially re-expandable to an implanted or deployed conditionlike that generally illustrated by FIG. 2.

The valves shown in FIGS. 1 and 2 are intended for implanting within apatient's native aortic valve to mitigate impaired functioning of thenative valve. FIGS. 1 and 2 do not necessarily show all features orcomponents of complete valves. For example, some layers of material(e.g., fabric and/or tissue) that may be used around the outside ofcertain portions of these valves are not shown in FIGS. 1 and 2 tobetter reveal possible constructional features of other components ofthe valves. In particular, FIGS. 1 and 2 primarily show thecollapsible/expandable, metal, stent frame 5010 of the depicted valves,and the flexible leaflets 5500 of these valves. (Again, fabric material(not shown) can be used outside or inside stent frame 5010 at the inflowsection of the stent.) Examples of suitable materials for leaflets 5500include biological tissue, polymer, thin metal, reinforced polymer, etc.As used herein, the term “biological tissue” includes such things asactual harvested porcine valves, bovine pericardium, and the like.

As in the above-mentioned reference, stent 5010 includes an aorticoutflow portion 5100 and an annulus inflow portion 5200. Portions 5100and 5200 are connected to one another substantially solely by at leastone connecting strut 5284. All of these structures (5100, 5200, and5284) are annularly or circumferentially collapsible (FIG. 1) andre-expandable (FIG. 2). This includes leaflets 5500. When the valve isin place in a patient's native aortic valve, the prosthetic valve isre-expanded as shown in FIG. 2. When the valve is thus re-expanded atthe implant site in the patient, annulus inflow portion 5200 istypically adjacent the patient's native aortic valve annulus, aorticoutflow portion 5100 is in the aorta downstream from the valsalva sinus(or downstream from at least part of the valsalva sinus), and connectingstruts 5284 pass through the valsalva sinus (or through at least part ofthe valsalva sinus). In addition, respective connecting struts 5284preferably pass near and on each side of each of the patient's nativevalve commissures. This last point will be described in greater detaillater in this specification. Because portion 5100 thus resides in thepatient's aorta when the valve is implanted, portion 5100 is generallyreferred to herein as the aortic outflow portion.

Annulus inflow portion 5200 includes three commissure posts or tipregions 5236 that are equally spaced from one another around the valve.In the FIG. 2 embodiment, for example, each of the commissure tips 5236is at the free apex of a V-shaped commissure post structure that extendsdown from the tip as viewed in FIG. 2. Each of these V-shaped commissurepost structures is cantilevered from at least an associated pair ofannularly spaced points on remaining structure of annulus inflow portion5200. Cantilevering the commissure posts in this way facilitates givingthe commissure posts desirable flexibility, which includes flexibilityin a direction that is radial of the valve at the location of the tip orfree end of each commissure post.

Adjacent each of commissure tips 5236, there is an associated pair ofconnecting struts 5284 a and 5284 b. One of these struts 5284 a is onone side of the associated commissure tip 5236 in a circumferentialdirection around the valve, and the other strut 5284 b is on the otherside of the associated commissure tip in a circumferential directionaround the valve. Each of these struts 5284 connects to the annulusinflow portion 5200 at a point that is well below the associatedcommissure tip 5236. As in the above-mentioned reference, this makes itpossible for the commissure post structure below each tip 5236 to bedesirably flexible relatively independently of struts 5284. It alsofacilitates giving commissure post structures 5236 and struts 5284shapes in the radial direction (i.e., inwardly and outwardly of thevalve as a whole) that can be relatively independent of one another. Forexample, commissure post structures 5236 can go relatively straight upfrom the base of annulus inflow portion 5200, while struts 5284 canbulge radially out from the geometric cylindrical surface in which thecommissure post structures lie. (The entire population of connectingstruts 5284 in a valve may sometimes be referred to collectively byreference number 5280.)

The connecting struts 5284 a and 5284 b that are adjacent to eachcommissure tip 5236 can remain relatively close to one another and tothat commissure tip as they extend to aortic outflow portion 5100. Thus,for example, in the annular (circumferential) direction around theexpanded valve (e.g., as in FIG. 2), and at the level (in the axialdirection along the valve) of commissure tips 5236, the struts 5284 aand 5284 b that are associated with each commissure tip 5236 tend to becloser to one another than they are to the circumferentially neareststrut 5284 that is associated with another commissure tip. This helps togive the valve relatively large openings 5140 between the struts 5284that are associated with annularly adjacent ones of the commissure tips.This may be desirable to help the valve avoid occluding the coronaryostia of the patient's coronary arteries. These ostia are located in thevalsalva sinus approximately midway between axial projections of certainof the native aortic valve commissures (see FIG. 3, which is discussedin more detail later in this specification).

To quantify an aspect of what is said above, at the level of commissuretips 5236 in the circumferentially expanded valve shown in FIG. 2, thewidth W1 of the opening 5140 between the struts 5284 associated with twoannularly (or circumferentially) adjacent commissures is preferablygreater than the width W2 between the struts associated with a givencommissure. More preferably W2 is less than about one-half of W1.

FIG. 3 shows the approximate cross-sectional shape of a typical nativevalsalva sinus 20. Axial projections of the commissures of the nativeaortic valve are indicated at 22. Locations of coronary artery ostia areindicated at 24. Between each annularly adjacent pair of commissureprojections 22, valsalva sinus 20 has an outwardly bulging lobe. The twoconnecting struts 5284 a and 5284 b associated with each prostheticvalve commissure pass axially through the valsalva sinus on respectiveopposite sides of the commissure projection 22 that is associated withthe prosthetic valve commissure 5236 that is aligned with thatprojection 22. These struts 5284 a and 5284 b also bulge radially out tofollow the bulge of the adjacent valsalva sinus tissue (see again FIG.2). From this it will be appreciated that the shape and locations ofstruts 5284 a and 5284 b can help to anchor the prosthetic valve in thedesired axial and angular location in the patient. The presence of apair of struts 5284 a and 5284 b adjacent to each side of eachcommissure projection 22 can help prevent the prosthetic valve fromrotating in the patient about the longitudinal axis of the valve. Inaddition, the outward bulging of struts 5284 into the outward bulging ofthe valsalva sinus lobes can help prevent the prosthetic valve frommoving in either direction along the longitudinal axis of the valve.These anchoring aspects of connecting struts 5284 passing throughvalsalva sinus 20 can be in addition to other anchoring aspects that theprosthetic valve may have (e.g., as shown and described in theabove-mentioned reference).

When deployed in a patient, all of the various prosthetic valveembodiments that are shown and described in this specification haveoutwardly bulging connecting struts 5284 like those shown in FIG. 2,with spacing (e.g., W1 and W2) like that shown in FIG. 2, and withpositioning of the struts relative to native valve commissureprojections 22 like that shown in FIG. 3.

FIG. 4 shows an alternative embodiment of stent frame 5010 (now labelled5010 a in FIG. 4). Although there are some differences between stent5010 a and stent 5010, the same reference numbers are generally used forgenerally similar parts of both embodiments (i.e., the embodiment ofFIG. 4 and the earlier-described embodiment of FIGS. 1 and 2). Whereasin the embodiment of FIGS. 1 and 2 both of aortic outflow portion 5100and annulus inflow portion 5200 are annularly continuous all the wayaround stent 5010, in the FIG. 4 embodiment stent 5010 a is annularlycontinuous as a whole, but each of portions 5100 and 5200 has severalinterruptions in the annular (circumferential) direction. In particular,where portion 5100 extends between two annularly adjacent connectingstruts 5284, portion 5200 does not extend between those two struts; andwhere portion 5200 extends between two annularly adjacent struts 5284,portion 5100 does not extend between those two struts. In other respectsthe prosthetic heart valve shown in FIG. 4 can be similar to what isshown in FIGS. 1 and 2, and it can implant in a patient similarly towhat is shown in FIG. 3.

An embodiment like that shown in FIG. 4 may fit better in certainpatients. For example, it may fit better in an irregular native aorticvalve annulus (e.g., an annulus that is made irregular by a congenitaldefect or by the presence of calcified native leaflet material). Apurpose for this embodiment is to provide flexibility in sizing of thedistal section (e.g., aortic outflow portion 5100). The intention of theinflow side is not to conform to native geometry, but rather to remodelthat geometry to allow the prosthetic valve to function optimally. Thepresence of hard calcification can impact the final deployed shape. Thisdesign allows some balance between remodeling and conforming.

FIG. 5 shows another alternative embodiment of stent frame 5010 (nowreferenced 5010 b in FIG. 5). Again, the same reference numbers usedearlier are used again for generally similar elements of FIG. 5. In FIG.5 aortic outflow portion 5100 is annularly continuous (as in FIGS. 1 and2), but annulus inflow portion 5200 is annularly interrupted in the sameway that the annulus inflow portion is interrupted in FIG. 4. In otherrespects the FIG. 5 embodiment may be similar to the previouslydescribed embodiments, and it can be implanted in a patient asillustrated in part in FIG. 3. Like the embodiment of FIG. 4, theembodiment of FIG. 5 may fit better in certain patients, such aspatients with an irregular native aortic valve annulus.

Note that in any of the embodiments shown and described herein, thestent frame can be provided with eyelets, apertures, or other featuresthat facilitate attachment of the leaflets and other materials to thestent. Examples will be shown and described later in this specification.

FIG. 6 shows yet another alternative embodiment of stent frame 5010 (nownumbered 5010 c in FIG. 6). Once again, the same reference numbers usedearlier are used again for generally similar elements in FIG. 6. Stent5010 c is basically the same as stent 5010, with the addition of aplurality of anchor members 5201 that are resiliently biased to inclineoutwardly from annulus inflow portion 5200. During delivery of the valveinto a patient in an annularly compressed or collapsed condition, anchormembers 5201 can be deflected substantially parallel to the longitudinalaxis of the valve. When the valve is released from such annularcompression for deployment in the patient (e.g., by pushing the valveout of the distal end of a delivery tube that keeps the valve annularlycompressed), anchor members 5201 spring out as shown in FIG. 6. In thiscondition anchor members 5201 engage (e.g., penetrate) the adjacentnative tissue of the patient and thereby help to hold the valve in placein the patient. (FIG. 3 again applies to the deployed condition of theFIG. 6 embodiment.)

It will be appreciated that anchors like 5201 can be used at any of manydifferent locations on the stent frame 5010, etc., of any of theembodiments shown herein. As just one example of other possiblelocations for anchors like 5201, such anchors could be alternatively oradditionally located on the upper (outflow) edge of any of the stentframe shown herein.

FIGS. 7a and 7b show illustrative embodiments in which an inflow-endcuff 5203 (e.g., of fabric) is included. Except for the addition ofinflow cuff 5203, the embodiments shown in FIGS. 7a and 7b can besimilar to any of the other embodiments shown herein. (FIGS. 7a and 7binclude greatly simplified depictions of the leaflet structure 5500 inthe open condition.) Inflow cuff 5203 preferably extends annularly allthe way around the valve adjacent to its inflow edge. (As alwaysthroughout this specification, “inflow” refers to the direction of bloodflow through the valve after it has been implanted and is in use in apatient.) The cuff fabric material can be attached to the outside (FIG.7a ), the inside (e.g., between stent frame 5010 d and leaflets 5500 asshown in FIG. 7b ), or directly below the stent frame in anotherembodiment. Inside and outside are preferred because this allows forbetter integration of the leaflet material 5500 onto the stent 5010 d,because the leaflet materials utilize the presence of the cuff fabricmaterial during assembly and integration. This also provides a moredurable design. When the valve is in the expanded state, the cuff fabricmaterial should lie flat on the inside or outside of the stent frame5010 d. The presence of the fabric 5203 helps promote tissue in-growthafter the valve has been implanted. This helps to seal the valve againstperivalvular leakage. (FIG. 3 again applies to the deployed condition ofthe FIGS. 7a and 7b embodiments.)

FIGS. 8 and 9 show another illustrative embodiment in which stent frame5010 e includes commissure regions that are somewhat more post-like, asat reference number 5237. (FIG. 8 shows the apparatus in its annularlyexpanded, deployed condition. FIG. 9 shows part of the same apparatus inits annularly collapsed, delivery condition.) Making each prostheticvalve commissure region more like a single upstanding post 5237 mayenhance each such commissure region's independent flexibility (i.e., itsability to flex independently of other parts of supporting structure5010 e). Amplifying the description of this aspect of FIGS. 8 and 9somewhat, in embodiments of this type, each commissure tip 5236 of thevalve is at the free end of a respective single structural member 5237that is cantilevered from a respective single point on remainingstructure of annulus inflow portion 5200.

FIGS. 8 and 9 also show examples of how stent frame 5010 e may beprovided with apertures 5239 for facilitating attachment of othercomponents (e.g., leaflets 550) to the stent frame. Another possible usefor apertures like 5239 is for helping to releasably secure a prostheticvalve in accordance with the invention to delivery system apparatus forthe valve. For example, wires or suture material may pass throughapertures like 5239 from and/or to delivery apparatus to help releasablyhold the valve in the delivery apparatus until the valve is ready to bedeployed into the patient. FIG. 3 again applies to deployment of theFIG. 8-9 embodiment.

FIG. 10 shows an example of a stent frame 5010 f that (solely forpurposes of illustration herein) has been cut along a longitudinal axisand then flattened. In the FIG. 10 embodiment the inflow edge of thestent frame (toward the bottom of FIG. 10) is scalloped or recessed sothat it is relatively “high” in the vicinity of each commissure region5236 and relatively “low” between each annularly adjacent pair ofcommissure regions. The high areas are pointed out by referencecharacters H, and the low areas are pointed out by reference charactersL. Making the inflow edge of stent frame 5010 f relatively high adjacentthe aortic valve commissures helps the prosthetic aortic valve avoidpossibly impinging on the patient's native mitral valve, and may alsohave other advantages.

FIG. 10 also illustrates some other possible variations. For example,FIG. 10 shows another possible arrangement of apertures 5239 like thosementioned above. FIG. 10 shows another arrangement of thecircumferentially collapsible/expandable ring structures that can beused in areas 5100 and 5200. In this example these ring structuresinclude four-sided, open-centered cells (e.g., 5105 and 5205) that canexpand in the left-right direction as viewed in FIG. 10 to annularlyexpand the stent frame for deployment in the patient, or that can shrinkin the left-right direction as viewed in FIG. 10 to annularly collapsethe stent frame for delivery into the patient. FIG. 10 shows these cells5105 and 5205 in their annularly collapsed condition. A row of suchcells can be thought of as two side-by-side serpentine or undulatingrings that are 180° out of phase with one another and that have beenjoined together at adjacent peaks in their undulations. FIG. 10 alsoshows another example of use of barbs 5201 like those described earlierin this specification.

FIGS. 11 and 12 show a representative detail from FIG. 10. It will beunderstood that this type of feature can be used at any suitablelocation(s) in any of the embodiments shown herein. The feature detailedin FIGS. 11 and 12 is a rounded corner 5207 between otherwise relativelystraight members of cells like 5205 or other similar serpentine orundulating ring structures. (Again, this feature can also be usedelsewhere such as in region 5100.) FIG. 11 shows one representativerounded corner 5207 in an annularly collapsed structure. Note that inFIG. 11 rounded corner 5207 preferably has an overall C shape. FIG. 12shows the same rounded corner after annular expansion of the structure.Now (i.e., in FIG. 12) corner 5207 has opened up somewhat to have a morenearly U shape. Use of these rounded corners helps to avoid stressconcentration where the members of the cellular or serpentine structurechange direction. This can improve the performance and extend the lifeof the structure. Also, upon expansion, these rounded corners tend toopen up slightly (e.g., from a C shape to a U shape). This canfacilitate leaflet attachment by providing locations through whichsuture material 5209 can be passed (e.g., as shown in FIG. 12).

FIG. 13 shows (using the same general type of depiction as in FIG. 10)yet another alternative embodiment in which aortic outflow portion 5100has more closed cells 5105 than annulus inflow portion 5200. This mayfacilitate annular expansion of aortic outflow portion 5100 to a largerdiameter than annulus inflow portion 5200. FIG. 13 also shows anotherexample of how and where aperture 5239 may be provided in stent frame5010 g to facilitate attachment of leaflets and other materials to thestent frame. (FIG. 3 again applies to deployment of embodiments likethose shown in FIGS. 10 and 13.)

FIG. 14 shows that a valve in accordance with the invention may havefabric 5206 mounted internally of any portion of stent frame 5010 (theFIG. 14 example shows fabric 5206 between annulus inflow portion 5200and leaflets 5500). FIG. 14 also shows that a valve in accordance withthe invention may have fabric 5208 mounted externally of any portion ofstent frame 5010 (again, the FIG. 14 example shows fabric 5208 aroundthe outside of annulus inflow portion 5200). Although FIG. 14 showsfabric around both the inside and outside of a portion of stent frame5010, it will be understood that fabric may be used in only one of theselocations if desired. Some or all of the fabric like 5206 and/or 5208may form the cuff 5203 shown in FIG. 7a or 7 b.

FIG. 15 shows that a valve in accordance with the invention may havetissue material 5206 a as a buffer between the stent frame 5010 andcoapting leaflets 5500 to prevent abrasion of the leaflets by the stentframe and provide longer durability performance for the valve. In theexample shown in FIG. 15, tissue material 5206 a is between annulusinflow portion 5200 and leaflets 5500. Tissue material 5206 a ispreferably thinner than the material used for leaflets 5500.

FIG. 16 shows (using the same general type of depiction as in FIG. 13)another illustrative embodiment of stent frame 5010 h in which eachcommissure post region 5237 is bifurcated into two, substantiallyparallel, independently cantilevered post members 5237 a and 5237 b.

In general, it is preferred that the circumferential (annular, radial)collapse and re-expansion of prosthetic valves in accordance with thisinvention is elastic or at least mostly elastic. However, part or all ofsuch collapse and/or re-expansion may alternatively or additionallyresult from use of shape-memory properties of the material of the stentframe (e.g., 5010) of the valve. As still another possibility, some orall of the collapse and/or re-expansion of the valve may be plastic. Forexample, such plastic re-expansion may be produced by inflation of aballoon (e.g., on a catheter) inside the valve.

It will be understood that the foregoing is only illustrative of theprinciples of the invention, and that various modifications can be madeby those skilled in the art without departing from the scope and spiritof the invention. For example, the number of undulations or cells usedin aortic outflow portion 5100 and/or annulus inflow portion 5200 can bedifferent (more or less) than the numbers shown in the FIGS. that formpart of this disclosure.

The invention claimed is:
 1. A prosthetic heart valve, comprising: anannular stent frame having an expanded condition and a collapsedcondition, the stent frame including an annulus inflow portion, anaortic outflow portion, and a plurality of connecting struts, each ofthe connecting struts having a first end connected to the annulus inflowportion and a second end directly connected to the aortic outflowportion, the annulus inflow portion including a plurality of commissurestructures that are spaced from one another in an annular directionaround the annulus inflow portion, each of the commissure structuresbeing cantilevered from at least a respective single point on aremaining structure of the annulus inflow portion not part of thecommissure structures, each of the commissure structures having anassociated pair of connecting struts disposed on opposite sides of thecommissure structure in the annular direction, the annulus inflowportion being devoid of structure between each commissure structure andthe associated pair of connecting struts; and a plurality of valveleaflets supported by the annulus inflow portion.
 2. The prostheticheart valve as claimed in claim 1, wherein each of the commissurestructures is cantilevered from a respective pair of points on theremaining structure of the annulus inflow portion.
 3. The prostheticheart valve as claimed in claim 1, wherein each of the commissurestructures has a free end defining a commissure tip, the commissure tipsbeing the features of the annulus inflow portion that are closest to theaortic outflow portion.
 4. The prosthetic heart valve as claimed inclaim 3, wherein each of the commissure tips is at an apex of a V-shapedstructure that is cantilevered from a respective pair of the connectingstruts.
 5. The prosthetic heart valve as claimed in claim 4, wherein theannulus inflow portion is devoid of structure other than the connectingstruts and the V-shaped structures.
 6. The prosthetic heart valve asclaimed in claim 5, wherein each of the V-shaped structures includes afirst one of the connecting struts positioned on one side of theV-shaped structure and a second one of the connecting struts positionedon an opposite side of the V-shaped structure, the first connectingstruts alternating with the second connecting struts in the annulardirection around the annulus inflow portion, for each of the V-shapedstructures the annulus inflow portion being devoid of structure betweenthe second connecting strut associated with the V-shaped structure andthe first connecting strut associated with an adjacent one of theV-shaped structures.
 7. The prosthetic heart valve as claimed in claim3, wherein each of the connecting struts is connected to the annulusinflow portion only at a respective point that is farther from theaortic outflow portion than each of the commissure tips.
 8. Theprosthetic heart valve as claimed in claim 1, wherein an edge of theannulus inflow portion that is most remote from the aortic outflowportion includes a recessed edge portion aligned with at least one ofthe commissure structures, the recessed edge portion being closer to theaortic outflow portion than other portions of the edge of the annulusinflow portion.
 9. The prosthetic heart valve as claimed in claim 1,wherein each commissure structure has a first end and a free end, thecommissure structure being connected to the annulus inflow portion onlyat the first end.
 10. The prosthetic heart valve as claimed in claim 1,wherein each of the commissure structures includes two post membersspaced apart from one another in the annular direction.
 11. Theprosthetic heart valve as claimed in claim 10, wherein each of thecommissure structures is cantilevered from a respective pair of pointson the remaining structure of the annulus inflow portion.
 12. Theprosthetic heart valve as claimed in claim 1, wherein the annulus inflowportion includes a plurality of diamond-shaped cells, each of the cellshaving a first apex pointing toward the aortic outflow portion and asecond apex pointing away from the aortic outflow portion, each of thecommissure structures being cantilevered from the first apex of arespective one of the cells.
 13. The prosthetic heart valve as claimedin claim 1, further comprising a plurality of anchor members that areresiliently biased to incline outwardly from the stent frame.
 14. Theprosthetic heart valve as claimed in claim 1, wherein each of thecommissure structures includes an aperture.
 15. The prosthetic heartvalve as claimed in claim 1, wherein each commissure structure is joinedto the remaining structure of the annulus inflow portion at anintersection, each intersection including an aperture.
 16. A prostheticheart valve, comprising: an annular stent frame having an expandedcondition and a collapsed condition, the stent frame extending from aproximal end to a distal end and including an annulus inflow portion atthe proximal end, an aortic outflow portion at the distal end, and aplurality of connecting struts connecting the annulus inflow portion tothe aortic outflow portion, the annulus inflow portion including aplurality of commissure structures that are spaced from one another inan annular direction around the annulus inflow portion, each of thecommissure structures being cantilevered from a respective pair ofpoints on a remaining structure of the annulus inflow portion not partof the commissure structures, each of the commissure structures having afree end and an associated pair of connecting struts disposed onopposite sides of the commissure structure in the annular direction, thefree ends being features of the annulus inflow portion that are closestto the aortic outflow portion, and the annulus inflow portion beingdevoid of structure between each commissure structure and the associatedpair of connecting struts; and a plurality of valve leaflets supportedby the annulus inflow portion.
 17. The prosthetic heart valve as claimedin claim 16, wherein an edge of the annulus inflow portion that is mostremote from the aortic outflow portion includes a recessed edge portionaligned with at least one of the commissure structures, the recessededge portion being closer to the aortic outflow portion than otherportions of the edge of the annulus inflow portion.
 18. The prostheticheart valve as claimed in claim 16, wherein each commissure structurehas a first end opposite the free end, the commissure structure beingconnected to the annulus inflow portion only at the first end.
 19. Theprosthetic heart valve as claimed in claim 16, wherein the free end ofeach of the commissure structures is at an apex of a V-shaped structurethat is cantilevered from a respective pair of the connecting struts.